Ah. Yes, you can easily run a 1.1 component library on 1.2 (e.g. Trinidad trunk, ajax4jsf). I'm not entirely sure *why* they are checking for UIComponentBase (this certainly isn't a requirement for the component to be a 1.2 component), but I guess its to ensure that 1.1 components have those reasonably behaved implementations of 1.2 methods. Let's see what they say :) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4071775#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...